Citing a few examples, a tool support is here understood to be a spindle, a chuck, a drilling tool, or the like, in particular a tool holder in accordance with DIN 69880, such as is known in actual use in a multitude of embodiments for fixed and rotating tools. Tool holders with collet chuck receivers are described, for example, in German Utility Model 90 03 730, in EP 0 416 611 B1 and in DE 199 58 461 C1.
Collet chuck receivers and the associated collet chucks are standardized in accordance with DIN 6499. Among them are collet chuck receivers wherein the associated tensioning nut has an external screw thread or an internal screw thread. Collet chuck receivers and collet chucks are preferably employed for drilling purposes, but generally also in those cases where a very exact, clamping with close tolerances, in particular of tools with a cylindrical shaft, or also cylindrical workpieces, is important. Other, special receivers are mainly required for receiving face milling cutter, circular saw blades, disk milling tools and sawing-out tools, etc., however, such tools can also be clamped in collet chucks by means of appropriate receiver mandrels and receiver shafts. In case of extremely tight space conditions, such as exist for example in NC-controlled lathes with pivotable tool supports, frequently only those collet chuck receivers can be used, which have a tensioning nut with an external screw thread. The external screw thread of this tensioning nut is intended for being screwed into an internal screw thread associated with the tapering bore of the collet chuck receiver. But, especially because of the restricted space conditions, the manipulation, and in particular the tightening of such a tensioning nut is often comparably difficult and time-consuming. However, tool receivers of different construction as a rule have a greater space requirement than collet chuck receivers and can therefore often not be employed under restricted space conditions, for example in the case of tool holders. Similar also applies to clamping systems wherein the clamping of the tool shaft or the like takes place from the back, facing away from the tool side, for example by using a screw-thread spindle arranged in a work spindle. In the case of tool holders arranged on turret disks, clamping systems of this type can basically not be used.